Clevis



D. H. BEAL May 16, 1967 CLEVIS 2 Sheets-Sheet 1 Filed Aug. 25, 1965 INVENTOR. DAVID H. BEAL Attorney May 16, 1967 D. H. BEAL 3,31

CLEVIS Filed Aug. 25, 1965 2 Sheets-Sheet 2 I I I l IN VENTOR. DA V/D H. BEAL Attorney United States Patent 3,319,990 CLEVIS David Hugh Bea], Burlington, Ontario, Canada, assignor to Donald Ropes & Wire Cloth Limited, Hamilton, 0ntario, Canada Filed Aug. 23, 1965, Ser. No. 481,850 2 Claims. (Cl. 29474) This invention relates to a clevis, and more particularly to a clevis used in the logging industry.

In the present time, tractor skidders are used for the transporting of logs, particularly pulpwood, in non-mountainous areas in which the logging industry is carried on. Use of a skidder permits a powered vehicle reach the felled wood without thenecessity of cleared, drained or graded access; and to move the wood considerable distances with speed and economy.

In moving wood with a skidder, a winchline or mainline is dragged behind it, and short lines called chokers are attached to the mainline and around the logs to be moved. The skidder then drags a number of logs at one time behind it; each attached to its own choker, and each choker attached to the mainline.

The material with which the mainline and chokers are usually made is a wire rope of the known varieties. In the past, however, the consumption of wire rope, particularly when used as chokers, has been unduly high. This high consumption is due, most particularly, to the use of improper attachments of the chokers to the mainline.

The present invention overcomes this difficulty in a new and unique fashion, and contemplates an improved clevis for attaching the choker to the mainline.

The invention is discussed with respect to the accompanying drawings, in which:

FIGURE 1 illustrates a choker utilizing the present invention;

FIGURE 2 illustrates an exploded view of the clevis of the present invention;

FIGURE 3 is a cross-section along line 33 in FIG- URE 2 and;

FIGURE 4 is a plan view from the top of the clevis of the present invention.

As mentioned previously, an undue consumption of wire rope, particularly when used as chokers, has occurred in the logging industry. Oftentimes, the same attachment device has been used for attaching the choker to the mainline as that used for closing the choker on the log. This has resulted in a bending fatigue of the choker rope behind the attachment to the mainline; since the logs drag generally in the line of direction in which the skidder is moving, but the choker rope comes off from its attachment to the mainline at approximately right-angles to it. Thus, considerable bending stress was impressed in the rope, and ultimately, premature failure.

The clevis of the present invention presents an open, thimble-shaped eye which permits free movement along the mainline and which eliminates snagging on the mainline. Also, there is a reinforcement of the forward face of the clevis between the eye and pin hole location.

When used with a choker rope, as shown in FIGURE 1, the clevis is connected to choker rope 11 by choker terminal fitting 15 and pin 13. A choker hook 21 of any known design is placed over the rope for closing the choker on a log. Choker terminal fitting 15 is free to rotate about pin 13, as will become more evident hereafter.

FIGURE 2 illustrates the clevis 10 in exploded view, with the forward face thereof turned upwards. A reinforced area 22, between the eye and the pinholes 14, is formed in the forward face. Also, a groove 17 may be formed on the outward face of the wall 19 around the eye, presenting the large internal bearing radius to the mainline attained by the curved profile of the inner face of the wall while providing maximum strength-to-weight ratio. Choker terminal fitting 15 is arranged to fit between the pinholes 14 and is held by pin 13. The pin 13 is maintained in position by any known arrangement, such as keying, cotter pins, lock rings, threaded nuts, upsetting etc. Choker terminal fitting 15 is arranged to have the choker rope 11 swaged therein, or held by any other suitable means.

The reinforced area 22 is on the forward face of the clevis. The pinholes and surrounding walls may be offset laterally, as shown, so that the forward face of the clevis is smooth .and substantially fiat. Undercut 12 is beneath the reinforcement 22, and defines, along with the surrounding walls of pinholes 14, the space in which the end of the choker terminal fitting 15 is free to swing around pin 13. Thus, the choker rope is free to drag behind the clevis as it is held on the mainline; and because of the swinging freedom of fitting 15, no bending stress in the choker rope is caused.

The cross-sectional view of the clevis in FIGURE 3 shows more clearly the substantially flat forward face. Also, shaded area 20 indicates the reinforcement 22, the shape of the web between the eye and pinholes 14, and undercut 12. Underside 18 is offset rearwardly to attain the substantially flat forward face. The relatively slim cross-section and the offset pinholes allow excellent nesting characteristics of the clevis when several are being carried on the same mainline. Also, when the clevises are nesting, reinforcement 22 serves to prevent undersides 18 of the pinhole walls from jamming in the pinhole area of the clevis beneath, by providing deflection of the clevises one from another.

The reinforcement 22 also strengthens the clevis jaws: and protects the choker terminal fitting, thereby reducing the possibility of clogging as the line is dragged over the ground.

The clevis, pin and choker terminal fitting may be manufactured from any suitable materials. In practice, steels such as CrMo steel and high Mn steel (10% Mn) have been utilized successfully.

While a preferred embodiment of the clevis of the present invention has been shown and described, it will be understood that various changes and modifications may be made in the details thereof without departing from the spirit and scope of the appended claims.

I claim:

1. A mainline clevis for use in the logging industry comprising:

a thimble-shaped eye defined by a surrounding wall;

a pair of jaws disposed rearwardly of said eye and having in each jaw an opening, said openings being on a common axis, which axis is substantially perpendicular to the axis of said eye;

a groove formed in the outer face of the wall defining said eye;

said wall comprising .at least at the forward end of said eye furthest from said pair of jaws a substantially large bearing radius in the inner face thereof, having regard to the face-to-face thickness of the clevis;

a reinforcement in one face of the clevis extending rearwardly from said eye and at least partially between said jaws, and defining thereby an undercut beneath said reinforcement, behind said eye and between said jaws to permit swinging engagement of a choker terminal held between said jaws by pin means through said openings therein;

the face of said clevis comprising said reinforcement being substantially flat and the opposed face of said 3 clevis being offset away from said first-mentioned face at said jaws. 2. A choker for use in the logging industry comprising: a choker rope consisting of a length of wire rope;

a choker hook adapted to be fitted to one end of said rope;

a clevis fitted to the other end of said rope and comprising:

a thirnble-shaped eye defined by a surrounding wall;

a pair of jaws disposed rearwardly of said eye and having in each jaw an opening, said openings being on a common axis, which axis is substantially perpendicular to the axis of said eye;

a groove formed in the outer face of the wall defining said eye;

said wall comprising at least at the forward end of said eye furthest from said pair of jaws a substantially large bearing radius in the inner face thereof, having regard to the face-to-face thickness of the clevis;

a reinforcement in one face of the clevis extending rearwardly from said eye and at least partially between said jaws, and defining thereby an undercut beneath said reinforcement, behind said eye and between said jaws to permit swinging engagement of a choker terminal held between said jaws by pin means through said openings therein;

the face of said clevis comprising said reinforcement being substantially flat and the opposed face of said clevis being offset away from said first-mentioned face at said jaws.

References Cited by the Examiner UNITED STATES PATENTS 297,882 4/1884 Waggoner 287-100 982,113 1/1911 Ashdown.

7/1942 BosWort-h 287-100 20 BERNARD A. GELAK, Primary Examiner. 

1. A MAINLINE CLEVIS FOR USE IN THE LOGGING INDUSTRY COMPRISING: A THIMBLE-SHAPED EYE DEFINED BY A SURROUNDING WALL; A PAIR OF JAWS DISPOSED REARWARDLY OF SAID EYE AND HAVING IN EACH JAW AN OPENING, SAID OPENINGS BEING ON A COMMON AXIS, WHICH AXIS IS SUBSTANTIALLY PERPENDICULAR TO THE AXIS OF SAID EYE; A GROOVE FORMED IN THE OUTER FACE OF THE WALL DEFINING SAID EYE; SAID WALL COMPRISING AT LEAST AT THE FORWARD END OF SAID EYE FURTHEST FROM SAID PAIR OF JAWS A SUBSTANTIALLY LARGE BEARING RADIUS IN THE INNER FACE THEREOF, HAVING REGARD TO THE FACE-TO-FACE THICKNESS OF THE CLEVIS; A REINFORCEMENT IN ONE FACE OF THE CLEVIS EXTENDING REARWARDLY FROM SAID EYE AND AT LEAST PARTIALLY BETWEEN SAID JAWS, AND DEFINING THEREBY AN UNDERCUT BENEATH SAID REINFORCEMENT, BEHIND SAID EYE AND BETWEEN SAID JAWS TO PERMIT SWINGING ENGAGEMENT OF A CHOKER TERMINAL HELD BETWEEN SAID JAWS BY PIN MEANS THROUGH SAID OPENINGS THEREIN; THE FACE OF SAID CLEVIS COMPRISING SAID REINFORCEMENT BEING SUBSTANTIALLY FLAT AND THE OPPOSED FACE OF SAID CLEVIS BEING OFFSET AWAY FROM SAID FIRST-MENTIONED FACE AT SAID JAWS. 